Rinse, pat dry and trim the duck legs (use the excess fat to render). Rub salt and herbs into duck legs allow to cure for 2 days covered in refrigerator. Melt duck fat and bring to 200 degrees. Rinse salt off of duck, pat dry and immerse in pan of duck fat, cover and cook for 3 1/2 hours. Remove from heat and allow to cool. Duck can be held refrigerated for several days. Before service remove duck from fat, discard skin (or use to make cracklings) and take meat from bone. Reserve duck fat.
In a small saucepan add halved shallots, honey and just enough water to cover; bring to a boil and simmer until tender and glazed, remove and reserve.
In a medium saute pan heat 1 tablespoon reserved duck fat, add potatoes, duck, walnuts, reserved shallots and toss until hot. Add chopped shallots, green beans, vinegar, salt and pepper and taste for seasonings.
Arrange in the center of plate, garnish with watercress tossed in olive oil and crouton brushed with farmers cheese.
In a non reactive saucepan, combine milk and slowly bring to 180 degrees. Strain through cheesecloth and allow to cool. When cool, place in a bowl, season, add herbs and lemon zest, to taste.